This one's just a news report, but it provides a data point for automated greenhouse operations.
That point is 1.2 pounds of vegetables per square foot per month, or 5.86 kg/m² per month (195g/m²*day). That's only 10 m² to feed a person just under 2kg of food per day.
This is a prototype. Improvements to the design are certain to occur, as are improvements to yield. The article mentions species-specific programming, so the environment and care of each crop is tailored to its specific needs. Even without these improvements their demonstrated yields are more than twice as high as my estimates for growing area. Imagine what could be done in a vertically dense, LED-lit soilless system.
I would like to see a system that can handle the whole process end to end: seeding, sprouting, transplanting, training, harvesting, disposal and cleanup. It could be general-purpose agricultural robots or a dedicated piece of hardware for each task or some hybrid, but this will be done sooner rather than later. Research in this field would help future space travelers and colonists while simultaneously helping to feed hungry people on Earth. This is exactly the kind of experimentation we as a society should be promoting.
There's a second data point in the article: $350,000 to build a 15,000ft² (1393m²) automated greenhouse. $251.26 per m² is higher than normal greenhouse construction, but only by perhaps 25% compared to a commercial-sized glass and aluminum structure (references suggest $20/ft²). Again, this is a prototype done as a one-off construction. Economies of scale would apply if the structure and its mechanical works were standardized and mass produced.